1. Field of the Invention
The present invention relates to a home network, and more particularly, to a method of controlling Quality of Service (QoS) of a service provided by devices in a universal plug and play (UPnP) network.
2. Description of the Related Art
Universal plug and play (UPnP) is a protocol capable of finding and controlling electric appliances connected to a network. UPnP is used as a standard technique of home networking.
The UPnP QoS architecture is a standard for securing QoS for services in the network by controlling traffic communicated among a plurality of devices in the UPnP network. Services such as QoS device services, QoS policy holder services, QoS manager services, and the like are defined in the UPnP QoS architecture. The UPnP QoS architecture is used to use multimedia contents such as audio and video through a network.
FIG. 1A illustrates a UPnP network constructed with a device for providing a QoS device service (hereinafter, referred to as a QoS device), a device for providing a QoS policy holder service (hereinafter, referred to as a policy holder), and a device for providing a QoS manager service (hereinafter, referred to as a QoS manager). A user previously sets and stores a traffic policy (for example, priority) in a network in the policy holder. When a control point requests QoS for predetermined traffic to be secured, the QoS manager constructs a traffic descriptor by receiving traffic policy information and controls traffic of the QoS devices by using the traffic descriptor.
FIG. 1b is a flow diagram for illustrating a procedure in which UPnP QoS architecture elements communicate with one another.
The control point transmits information on traffic to which QoS is to be applied to the QoS manager by calling an action of RequestTrafficQos( ) of the QoS manager service. The transmitted information may include types of source devices, sink devices, and traffic.
The QoS manager acquires a traffic policy by calling an action of GetTrafficPolicy( ) defined in the QoS policy holder service based on the transmitted information. The traffic policy indicates information for controlling QoS for the traffic such as an admission policy, a traffic importance number, a user importance number, and the like. Since a detailed description of information constituting traffic elements is included in UPnP QoS architecture document, a detailed description thereof will be omitted. On the other hand, the QoS manager calls the actions of GetPathInformation( ), GetQoSDeviceInformation( ), and GetQoSState( ) defined in the QoS device service so as to recognize a path of the traffic and capability of devices located on the path of the traffic.
Finally, the QoS manager controls traffic of the QoS devices by calling an action of SetupTrafficQos( ) of the QoS device services based on the gathered information.
In the existing technique, since a traffic policy has to be set, there is a problem in that it is impossible to flexibly control the traffic of the network for different situations and different users. For example, when a user sets a priority level of video traffic transmitted from a media server located at an upstairs room to a television (TV) in a living room to the highest priority level, the video traffic has the highest priority level regardless of the situation, if a traffic policy for the video traffic is not changed. However, as an example, QoS of video traffic of a drama transmitted from a set-top box in the living room to a kitchen has to be previously set to coincide with a time for preparing a dinner. In a case where an urgent report has to be printed, data traffic transmitted to a printer is most important for the user. The existing technique is inconvenient because traffic policies have to be changed in the aforementioned cases.